I use pdfcreator as a virtual printer to transform files like docs to pdf in a delphi program. Also when I transform the file I put a password to protect it. Sometimes the user choose a pdf document to transform (it doesn't need to be transformed, only it just be protected with a password but I don't know how to do it), then, delphi opens the doc with acrobat reader and pdfcreator but it hungs up. There is no problem if you close acrobat reader later but the user shouldn't have to do this. Somebody can help me?
you could try to use a different PDF reader and set it as default and see if this still happens, at the moment I can´t tell if PDFCreator or Adobe Reader is causing this behaviour.